Two teenage girls had to break out of their own school after being locked in overnight.

The Year 11 pupils spent the night trapped in an outdoor courtyard at Whalley Range High School for Girls without food or water.

Both girls, one aged 16, only managed to escape more than 12 hours later by climbing out on to the roof of an adjacent building and jumping to safety the following day.

The pair had gone into school on Saturday morning for extra maths tuition.

School bosses are now investigating the incident and have changed procedures for weekend lessons.

After the lessons, the girls went into the outdoor quadrant area. But they became trapped when a firedoor closed and locked behind them – with staff unaware they were trapped.

Both girls’ families reported them missing to police when they failed to return home on Saturday night. Emergency services were contacted again when the girls arrived home on Sunday after their ordeal.

Police and paramedics were called to meet one 16-year-old girl at the school when she returned with her parents later on Sunday morning to speak to staff. She was said to be uninjured apart from a pain in her hand but ambulance bosses said she had been left ‘shaken’ by her ordeal.

Paramedics advised her to rest after going without food and water for so long.

The school, a specialist business and enterprise college on Wilbraham Road, said they are treating the incident ‘very seriously’.

Headteacher Patsy Kane said: “We’re investigating an incident in which two Year 11 pupils remained in school overnight following extra classes held in school at the weekend.

“A small part of the school building had been opened up to facilitate the classes, but the two students left the designated area via fire doors and were unable to return to this area after the doors locked shut behind them, leaving them in an enclosed outdoor quad.

“Although both families reported their daughters missing to the police later that evening, no contact was made with the school until the following morning.

“By this time the pupils had managed to get themselves out of the building by climbing onto the low level roof of the quad and had gone home.

“Both girls are safe and well but we take this very seriously and are talking to the pupils, their families and staff to understand exactly how this happened.

“We have also reviewed our arrangements for out-of-hours use of the school building and have put robust measures in place to ensure this can’t happen again.”